It is well established knowledge that the low-frequency response of a receiver can be boosted by providing a venting opening between the back volume of the receiver and the exterior of the receiver. By providing a properly dimensioned venting opening the back volume of the receiver may be vented via an orifice/acoustical impedance in a manner so that the back volume is fully vented at low frequencies (from around 5 Hz to around 1 kHz), i.e. the vented/open back volume configuration is favorable for low frequency reproduction. As the frequency increases the acoustical impedance also increases causing the back volume to be seen as a closed back volume at higher frequencies leaving a first resonance peak at the same frequency as the more favorable closed back volume configuration for high frequency reproduction. By carefully choosing the acoustical impedance as function of frequency the transfer/response curve of the receiver can be tailored to comply with specific demands.
Traditionally, venting openings are provided through a housing part of the receiver via a tube, a mesh or a damping cloth in order to provide a desired acoustical impedance. However, the traditional techniques for providing a venting opening are disadvantageous seen from a cost perspective as additional process steps and/or additional materials are often required. In addition, the risk of manufacturing defects or failures is affected by the additional process steps. Therefore, there is a need for providing venting openings in a more cost effective and easy manner.
It may be seen as an object of embodiments of the present invention to provide an advantageous arrangement in terms of manufacturing and costs for implementing a venting opening in a receiver in order to boost the low-frequency response of the receiver.